The human nose is a relatively complex structure that allows for the inhalation of air and exhalation of air and carbon dioxide and other cellular waste products. The nose also accomplishes physiological functions including humidification, temperature control and filtration of the inspired air. The nose additionally is a sensory organ responsible for the olfactory sense. For most people, the nose performs these functions efficiently and relatively trouble-free. However, patients often complain of symptoms relating to restricted airflow in their nasal passages. The septal cartilage structure of the nose divides the nose into two passages. These passages are typically described or referred to as nostrils. Inspired air moves through the nostrils, the nasal vault, and the nasopharyngeal wall, the pharynx, larynx, trachea, bronchi and reaches the alveoli in the lungs. Inhalation and exhalation are responsive to movement of the diaphragm and the intercostal muscles of the ribs. It is estimated that more than fifty percent of the total respiratory resistance of the respiratory tract occurs in the nose. It is known that airway obstruction in the nose may be attributable to various factors, including deviated septum, suboptimal position and rigidity of the lateral nasal walls, etc. The internal nasal valve is described as the space between the fold of the upper lateral cartilage (ULC) and the nasal septum. The angle between the septum and the upper lateral cartilage normally ranges between 10 and 15 degrees. It is generally accepted that nasal resistance behaves in accordance with Poiseuille's law and Bernoulli's principle, which means that small changes in the nasal valve area tend to have an exponential effect on the airflow. Patients with less than a ten degree angle at the internal nasal valve usually have airflow obstruction and are diagnosed with internal valve stenosis. The internal nasal valve may also be narrowed due to thickening of the septum or by a deviated septum. Additional causes of nasal obstruction include trauma to the nose, face or head, burns, and elective surgery. Surgery of the nose typically involves repositioning of the nose's bony and cartilaginous structures. Excessive scarring disc to aggressive resection may also lead to resultant narrowing of the nasal valve area. The internal valve may also become collapsed due to poor cartilage quality or position. As the internal valve collapses, the airflow becomes obstructed. The external nasal valve is composed of the nasal ala and supporting structures of the lower lateral cartilages.
These areas are named valves because they regulate the cross-sectional area of the nasal airway and perform dynamic functions. The collapse of the lateral nasal walls at the internal valve is known to be associated with a reduction rhinoplasty procedure commonly referred to as ‘hump removal’. During such reduction rhinoplasty, a hump in the cartilaginous and/or bony dorsum of the nose needs to be resected, which leads to reduction of the overall valve area and destabilizing of the ULC. The patient may experience post-surgical breathing problems if the nasal valve is not properly repaired after this procedure. This nasal valve reconstruction is typically done by the surgeon emplacing unilateral or bi-lateral spreader grafts on the nasal septum from the cephalic to the caudal portion of the nasal septum. Such devices and procedures widen the cross-sectional area of the upper nasal valve. However, there are deficiencies present in and associated with the use of conventional spreader grafts, which are typically made from autologous cartilage. The deficiencies include the need for autologous cartilage harvesting, resulting in donor site morbidity, and increased pain and duration of the procedure. Although non-absorbable spreader graft implants exist, surgeons prefer not to use them due to the increase risk of complications such as infection and extrusion.
Therefore, there is a need in this art for novel bioabsorbable, spreader grafts for nasal reconstruction procedures that increase the spacing between nasal upper lateral cartilages without using permanent foreign body material to achieve permanent repositioning of the upper lateral cartilages, and, which provide improved structural support in patients undergoing plastic or reconstructive surgical nasal procedures. There is also a need for novel bioabsorbable spreader grafts which promote tissue ingrowth and minimize long term complications, are relatively easy for the surgeon to implant, and provide a superior result and outcome for the patient.
As mentioned previously, rhinoplasty is a complex surgical procedure that involves the modification of underlying nasal structures such as bone, cartilage, ligaments and soft fibro-fatty tissue. The procedure may be performed for a variety of reasons that include improving the aesthetic appearance of the patient's nose; for reconstructive purposes following trauma; correcting various abnormalities of the nose that the patient may present; and, for correcting nasal passage functional problems associated with breathing for both inhalation and expiration. Regardless of the reasons for the rhinoplasty, the surgeon strives to restore or maintain functionality, remediate structural issues, and at the same time address aesthetic factors by creating and/or maintaining certain proportions between the various parts of the nose and face.
One of the most challenging aspects of rhinoplasty is generally considered to be the surgery of the lower third of the nose, mainly the nasal lip region. The stability of the nasal tip is important not only for the aesthetic look and appearance of the nose (e.g., tip projection and tip rotation), but also for physiological and anatomical functions such as appropriate inspiration and expiration, facial expression, and shock absorbance in response to facial trauma.
Preserving or creating adequate support of the nasal tip is important for both the immediate post-operative results, and, the long-term outcomes over the life of the patient. Due to factors such as scar contracture, thinning of the soft tissue envelope, and weakening of the cartilage structures with aging, some suboptimal results may be observed soon after surgery, and not infrequently. The consequent deficiencies can often become much more obvious, pronounced, apparent, and prevalent with the passage of time, usually about ten to fifteen years later.
It is known that skin thickness is a factor in determining how well the external skin cover will redrape over the underlying structures of the nose post-surgery. Patients with thin skin tend to have stronger cartilaginous structures, but the underlying structures are more visible, and a step-like transition between the bone and the cartilage can be seen. On the other hand, for patients having thick skin, obtaining proper definition and refinement can be a challenge.
One of the major support mechanisms of the nasal tip is the medial crura of the lower lateral cartilage (LLC). The foundation of the nasal tip is determined by the base (anterior nasal spine) and the footplates of the medial crura. Patients who have long and strong medial crura that extend to the nasal spine are more likely to have adequate tip support. In contrast, patients who have short medial crura, and flaring footplates at the mid-columella, are more likely to have poor tip support and lose tip projection after surgery.
Various surgical techniques and procedures that provide long-term support to the tip of the nose and stabilization of the nasal base have been used in the past. One of the widely used techniques is the placement of a columellar strut graft. The graft is usually and typically made of autologous septal or rib cartilage, which is sutured between the medial crus of the lower lateral cartilages. The columellar strut graft can extend to the nasal spine or be placed above the nasal spine. Another surgical method or procedure to provide nasal tip projection and support is the “tongue-in-the-groove” technique, wherein the medial crus of the lower lateral cartilages are sutured to the caudal end of the septum. A septal extension graft may also be used to ensure that the nasal tip projection is maintained postoperatively, or to correct an over-rotated tip in the case of revision surgery. Although nonabsorbable implants may be used to support the nasal tip, such a method of tip support treatment is not preferred by surgeons because of associated complications, including infection, skin necrosis, and implant extrusion, as well as factors such as patient awareness, and appearance.
In order to improve existing surgical procedures and patient outcomes, there is a continuing need in this art for low mass columellar struts with geometric characteristics that enhance the associated implantation procedure and provide for superior patient results. In particular, there is a need in this art for novel implants made from bioabsorbable polymers that are useful in nasal reconstruction surgical procedures.
A septal extension graft is typically constructed from a piece of autologous cartilage, which is connected to the septum to increase the nasal length and ensure appropriate nasal labial angle. The cartilage graft is connected to the native septum in a “end to end” fashion by means of additionally harvested strips of cartilage that are fixated on one or both sides of the septum and stabilize the structures. This current method requires additional harvested cartilage to achieve the repair and the cartilage strips add additional thickness and thus reduce the airflow though the nasal passages. There is a similar need for novel bioabsorbable polymeric septal extension grab devices.
Bioabsorbable polymeric plates are also known in the art for use in nasal reconstructive procedures. For example, the PDS Flexible Plate distributed by Ethicon, Inc., Somerville, N.J., may be used by the surgeon for nasal soft tissue and cartilage reconstruction to aid septoplasty and the construction of various grafts in rhinoplasty.
Since many nasal reconstructive procedures are directed to correcting multiple nasal structural deficiencies, it is often common to use a multiplicity of grafts and/or devices in one procedure, including but not limited to columellar struts and spreader grafts, as well as plates, septal extensions, etc. Accordingly, the hospital or health care provider is required to maintain an inventory of such devices in multiple sizes. It would be advantages to have a single polymeric bioabsorbable universal kit device that could be cut or trimmed by the surgeon in the field to form a variety of sizes and types of bioabsorbable nasal implant devices. It would be also desirable to have single unitary kit device that could be cut into several different devices.